Storage and waste containers are well known. The majority of such containers are made from steel. There are several disadvantages associated with the use of steel containers, chief among them being high weight and poor durability due to corrosion and rust. As such, several recent dumpster and container designs have instead employed plastic as the principle structural material. Thermoplastics are ideally suited to applications benefiting from decreased weight requirements and improved long term durability.
U.S. Pat. No. 3,669,485 provides an early example in which a dumpster is fabricated mainly from plastic. The dumpster has reinforced end walls to which two vertically spaced channel members are bolted, and which are designed to receive the tines of a forklift. The channel members define an elongated channel which is external of the container interior volume. Because the channel members are made of metal, they are subject to corrosion.
U.S. Pat. No. 4,550,849 discloses a refuse container made of thermoformable plastic and which is fabricated by rotational molding. The side walls of the container have upper and lower portions offset from one another and which are designed to receive a metal reinforcement sleeve in order to distribute loading stresses when the container is lifted by a pair of forklift tines. The metal sleeves are held within channeled areas which are entirely surrounded by plastic. There is no outwardly open elongate channel present. Hence, it would be difficult to replace the reinforcing sleeve if it should become necessary due to corrosion issues. Further, use of enclosed channel areas, generally requires that the container be molded with the metal sleeves already in place, a method which is not always desirable.
U.S. Pat. No. 5,183,180 describes a plastic refuse container in which each of the side walls and end walls has vertically oriented ribs to increase the structural rigidity of the container. The container includes metal lifting pockets which are bolted to the exterior of the container side walls. The refuse container can be fitted with lid structures. U.S. patent application Ser. No. 2008/0237251 discloses a similar refuse container made of plastic. Flanged fork pockets made of a metal material are bolted to the exterior side walls and partially wrap around the front wall of the container. The container side walls have outwardly offset upper areas which overhang the fork pockets slightly to help distribute the weight of the container to the side walls when the container is lifted by the fork pockets.
U.S. Pat. No. 5,330,071 teaches a large plastic refuse container in which fork pockets are present within an outwardly extending channeled area in each of the container side walls. The channeled area is enclosed on upper, lower and exterior surfaces. There is no teaching of an outwardly open elongated channel which can receive a metal insert. Instead, a tubular metal insert is placed in the channeled area through an inwardly facing elongate opening. The design of the outwardly positioned fork pockets prevent these containers from being deeply nestable.
U.S. patent application Ser. No. 2006/0045680 describes a rotomolded plastic container made from so called “vibration adsorbing material” such as linear low density polyethylene. The containers are fitted with a metal sleeve assembly which includes a fork pocket which is fixed to an exterior side wall surface.
U.S. patent application Ser. No. 2009/0179444 discloses a plastic dumpster which has removable and externally placed plastic sleeve members which can receive a lift member. Alternatively, the outwardly extending plastic sleeves may be integrally molded with the rest of the container body. In each embodiment of the invention, the sleeves are tubular. The container may also have beveled corner areas. The container does not possess outwardly open elongated channels and does not provide interior storage space above the location of the sleeve members.
U.S. patent application Ser. No. 2008/0197645 teaches a multi-modular waste container made of structural foam. The container has tiered interior and exterior surfaces and has detachably fastenable “arms” which engage each side wall. The arms define tubular areas which receive prongs or lift members. The tiered exterior and interior surfaces facilitate nesting of multiple containers, but such nesting requires removal of the attached arms.
U.S. Pat. No. 7,237,689 discloses a plastic waste container that is formed by rotational molding and which has integrally molded tine pockets. The plastic tine pockets have integrally molded struts which extend from the pocket along a side wall at positions above and below the pocket. The struts help to reinforce the tine pockets and distribute stresses to the walls when the container is lifted. The pockets extend outwardly from the container interior and can receive a metal or plastic insert to increase their overall strength. The pockets are fully surrounded by plastic walls and have no side opening. The pockets extend outwardly from the container interior, preventing the tight nesting of a plurality of such containers. There is also no interior storage space above the pocket areas.
Despite the above disclosures, there remains a need for new, improved containers, such as containers having greater strength around a tine pocket or channeled area and which permit facile exchange of vulnerable reinforcing elements such as tine pocket metal sleeves or inserts. Also desirable would be a deeply nestable container which does not require removal of external pockets or lift members prior to nesting. Finally, a container which combines interior storage space above a channel or tine pocket area, with greater strength and nestability features would be beneficial.